1. Field of the Invention
The present invention relates to a wireless communication system for accomplishing one-to-one and one-to-many bi-directional transfer of data and time synchronization information between a host system and a plurality of grouped or multiply-clustered remote devices. The invention is particularly directed to ground-, air-, or sea ship-based armament systems with Global Positioning System (GPS)-equipped munitions which require the downlink transfer of data and precise time to the munitions prior to their release to prepare guidance and targeting functions, enable rapid GPS receiver acquisition of the full military accuracy encrypted signal, and provide the uplink transfer of individual munition's launch preparation status information.
2. Description of the Related Art
Today's weapons systems increasingly rely on the use of precision guided munitions (PGM's) to improve the accuracy with which ordnance may be delivered to a target, thereby increasing the damage expectancy for each weapon, reducing collateral damage, and reducing the number of weapons and delivery platforms which must be utilized to achieve the desired level of damage. Reducing the number of weapons and sorties which must be committed to achieve a desired damage expectancy result minimizes crew exposure to enemy defenses and offers the potential for substantially reduced munitions and operations costs.
The transfer of target assignment, and other data initialization necessary to prepare a PGM's guidance system, and in many cases to a precision GPS navigational receiver as well, currently relies on a hardwire cable to each munition to transfer such information. The costs of installing and maintaining hardwire cable umbilicals to each weapon represent a significant fraction of the overall cost to field and operate a PGM munitions system.
Recent innovations to reduce the cost of upgrading host weapons systems to interface with PGM's have resulted in the elimination of the hardwire umbilical to PGM's, using instead a "virtual" hardwire connection consisting of some kind of wireless interface and self-contained munitions power. The Boeing Virtual Umbilical.TM. wireless weapon interface developed for a B-1B aircraft PGM, and now proposed for other aircraft and Naval gun systems, performs such an initialization function.
Present applicant, Gary A. Kinstler, is the inventor of U.S. Ser. No. 08/362,339, entitled "Virtual Umbilical Utilizing Infrared Serial Data Link", which teaches wireless downlink communications of data and time synchronization strobe for weapon guidance and GPS initialization utilizing a time division multiplex protocol over an infrared (IR) communication link. The '339 application provides no uplink communication channel for data such as status information. Present applicant, Gary A. Kinstler, is also the inventor of U.S. Ser. No. 08/721403 entitled "Remote Identification Location and Signaling Response System" which teaches uplink status information with a low-data-rate, spatially-discriminating communications sensor on the host side of the uplink. There may, however, be occasions where a higher uplink bandwidth is desired, and where uplink communications from individual remote devices can be alternatively managed with an individually-addressable command/response protocol, without the need for spatial discrimination.
As will be disclosed below, the present invention provides a high bandwidth data uplink which operates through, and is integrated with, the same network of distributed communications modules as used for the downlink, which is fully compatible with the time division multiplex protocol utilized for the downlink, and provides the capability for controlling the transfer of uplink data from individual munitions.
The method of this invention accomplishes bidirectional information transfer from the host system to each munition in a wireless fashion through a multiplexed network of distributed transceivers, as opposed to the use of hardwire umbilicals common in prior weapon system munitions launch preparation communications links.
The present invention provides a method and preferred embodiment for sharing the physical data transfer path to multiple distributed host transceivers for both downlink and uplink data and time transfer functions.